fix: Updated Korean translations

[FajarKim]

Description

I made some big changes for this translation. Here's an explanation:

1. Changes to the translation of "Longest Streek" and "Longest Week Streak"
   Previously used "최대" which literally means "biggest". I changed it to "최장" which means "longest". Also, added "연속" as the translation of "streak".
2. Changes to the translation of "Week Streak"
   Previously translated as "주간 기여 수" which only indicates the weekly contribution amount. I changed it to "주간 연속 기여수". The addition of "연속" as a translation of "streak".
3. Changes to the translation of "Excluding {days}"
   Previously translated as "{days} 제외된", which means "excluded {days}" (passive form), it is not precise in conveying the meaning of exclusion. I changed it to "{days} 제외하고".

If this needs to be discussed again, please feel free.

Type of change

• Bug fix (added a non-breaking change which fixes an issue)
• New feature (added a non-breaking change which adds functionality)
• Updated documentation (updated the readme, templates, or other repo files)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

• Tested locally with a valid username
• Tested locally with an invalid username
• Ran tests with composer test
• Added or updated test cases to test new features

Checklist:

• I have checked to make sure no other pull requests are open for this issue
• The code is properly formatted and is consistent with the existing code style
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Screenshots

None

[DenverCoder1]

Looks good to me, thanks for the update!